[NETFILTER]: nf_conntrack_ftp: fix missing helper mask initilization

Signed-off-by: NPatrick McHardy <kaber@trash.net>

net/netfilter/nf_conntrack_ftp.c

@@ -586,6 +586,7 @@ static int __init nf_conntrack_ftp_init(void)
 		for (j = 0; j < 2; j++) {
 			ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]);
 			ftp[i][j].tuple.dst.protonum = IPPROTO_TCP;
+			ftp[i][j].mask.src.l3num = 0xFFFF;
 			ftp[i][j].mask.src.u.tcp.port = 0xFFFF;
 			ftp[i][j].mask.dst.protonum = 0xFF;
 			ftp[i][j].max_expected = 1;